Universal circle divider



June 3, 1958 s. M. NXSENSON 2,836,892

UNIVERSAL CIRCLE DIVIDER Filed Sept. 21, 1.955

5 Sheets-Sheet 2 INVENTOR Jhzzhy/MMbe/zson ATTORNEY June 3, 1958 s. M. NISENSON 2,836,892

' UNIVERSAL CIRCLE DIVIDER Filed Sept. 21, 1955 5 Sheets-Sheet 3 53 &

INVENTOR ATTORNEY United States UNIVERSAL CIRCLE DIVIDER Stanley M. Nisenson, Brooklyn, N. Y.

Application September 21, 1955, Serial No. 535,547

1 Claim. (Cl. 33-1) The present invention relates to a universal circle divider, and it particularly relates to a circle divider which may be used for the sheet metal industries.

It is among the objects of the present invention to provide a novel circle divider and particularly a sheet metal la -out system which will more readily enable the manual sheet metal worker without undue complications or special instruments more readily to provide circular projections and particularly such projections in connection with cutting, forming and shaping sheet metal piping. Another object is to provide novel universal sheet metal dividers which may be widely used in drafting rooms and drafting classes, sheet metal layouts, the piping industry and in mapping and navigation.

Another object is to provide a time-saving, readily useable device for laying out sheet metal piping which may be easily used by relatively unskilled workmen as a projection aid for the miters of piping and duct fitting and which when made in wide range of sizes may be an aid in the layout of all fittings, joints and elbows in sheet metal and piping construction whose forms are based upon circles.

Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only, and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

In accomplishing the above objects it has been found most satisfactory according to the above embodiment of the above invention to make a clear plastic device having a plurality of radiating lines therein which will serve to divide a circle in 24 or 48 parts with a central blank space having an opening representing the center of the circle. There may be provided a fixed instrument, or a rotatable instrument in which a central radially perforated portion rotates within an encircling frame work. Generally the instrument is formed in rectangular clear plastic plate which may vary from to A3" in thickness with a plurality of radiating slots of decreasing dimension downwardly and with a central opening.

It is possible by the basic embodiment of the present invention to provide circle dividers of 48, 24, 12, 8, 6, 4, or 3 classification. For example, a unit with 12 divisions with intermediate lines for 24 divisions may be provided for a l" to 4 diameter unit.

A series of different sizes or groupings, as for example, one circle divider is to diameter; another circle divider is 3" to 8"; another circle divider is 6 to 12" diameter. and still another is for to 20 diameter and there may be larger diameters for special purposes.

With the foregoing and other objects in view the invention consists of the novel construction, combination and arrangement of parts as hereinafter more specifically described, and illustrated in the accompanying drawings, wherein is shown preferred embodiments of the invention, but it is to be understood that changes, variations and 2,835,892 Patented June 3, 1958 "ice modifications may be resorted to which fall within the scope of the claims hereunto appended.

In the drawings wherein like reference characters denote corresponding parts throughout the several views:

Fig. l is a top plan view of a preferred form of circle divider according to the present invention.

Fig. 2 is a transverse, vertical, sectional view upon the line 2-2 of Fig. 1 and upon the same scale as Fig. 1. I

Fig. 3 is a transverse sectional view upon an enlarged scale showing the slotted cross-section.

Fig. 4 is a top plan view of an alternative embodiment showing a rotary central element.

Fig. 5 is a transverse sectional view upon the line 55 of Fig. 4.

Fig. 6 is a top plan view of an alternative embodiment.

Fig. 7 is a transverse sectional view upon the line 7-7 of Fig. 6.

Fig. 8 is a fragmentary transverse sectional view upon the line 8-8 of Fig. 6.

Referring to Figs. 1 to 3, there is shown a clear plastic unit A having a plurality of radial downwardly converging or tapered through grooves B radially arranged around a central unslotted portion C. There is provided a central opening D which will enable the marking of the center of the circle.

in one preferred form of the invention the clear plastic forming the plate A is of thickness, and each radial slot may be indicated by a numeral 4, 8, 12, 24, while the circles may be indicated by the numerals 2, 3, 4, 5 as shown in Fig. 1.

it will be noted that there are four rectangular edges 16, 11 and 12 with a 30, 45", or 60 edge 13. The main circle markings 14 may be continuous and extend across the slots B and there may be intermediate short markings 15 indicating the half-way points. Each slot B as indicated in Fig. 3 has the downwardly converging side walls 16 so it may terminate in its narrow width to guide the scribe or tool or even pencil which may be employed. The central opening D also converges downwardly.

In using the device as shown in Figs. 1 to 3 the center of the circle guider D is placed on the center of the circle to be divided. Then a thin scribe or sharp pencil is inserted into the slots B to give the desired number of circle divisions. For example, one scribe line may be made through the slot 4 at the bottom of the divider and one each may be made as indicated at 3 in the upper right and left hand sides of the divider, thus dividing the circle into three parts.

To make four scribe lines on the sheet of metal each of the slots marked 4 may be used for a scribe marking.

For dividing the circle into six equal parts six scribe lines may be made, one at the original 4 and upper 3' lines, and the others in the also aligned slots.

For dividing the circle into 8 parts a scribe mark will be made in each of the four grooves marked 8 as well as in each of the four grooves marked 4.

For dividing the circle into 12 equal parts the mark will be inserted at each of the grooves marked 12 and also each of the grooves marked 4.

The circle may be divided in 24 equal parts by using all of the slots and 48 divisions may be obtained by using each of the 24 slots and then rotating the device so that the 48 line indicated at 17 will fall over one of the previously scribed lines whereupon 24 additional scribe lines will be applied.

In this manner it is possible to divide metal Work into 3, 4, 6, 8, 12, 24 and 48 divisions without any complicated calculations so that it may be more readily carried out by sheet metal workers without use of mathematics and without use of complicated tables or mathematical background,

In the embodiment of Fig. 4 there is shown the basic transparent stilf sheet material M having the square edges 25, 26 and with the interrupting upper edge 27 and 28.

The right sideedge is angular, and may be 30, or 60.

The fiat plate in Fig. 4 has a circular opening N which receives the rotating device Q having the handle R. This device has two opposite radial slots S which are graduated as indicated at T. The periphery of the cut-out is also graduated as indicated at U.

The arms 30 and 31 are sufficiently flexible so as to permit the circular element Q to be snapped into position with the projecting edge portions 32 fitting in the grooves 33 on the periphery of the circular portion Q.

At 90 positions away from the slots are provided the opposite openings 34. In the arrangement shown in Figs. 4 and 5 the same effect is achieved by. means of the disk Q which will permit the scribe lines to be marked in accordance with the graduations U of the circular element Q and at the radial distances indicated by the graduations T along the slots S.

The device shown in Figs. 4 and 5 may be utilized similarly to give the usual circle division marks corre sponding to dividing a circle in 3, 4, 6, 8, 12, 24 or 48 parts.

The device of Figs. 4 and 5 may also be employed to give various divisions of a circle by utilizing the radial graduations U on the plate M in combination with the slots S, and as indicated there may be also divisions in 2 to 13 parts as well as combinations thereof, such as 13 parts, 26 parts and 52 parts.

In either the embodiment of Figs. 1 to 3, or Figs. 4 and 5, the division lines may be varied to divide a circle in any number of equal parts and to enable ready projection of the circle upon sheet metal parts which are to be used for junctions between pipes or conduit connections. A pencil, scribe or other marking tool may be readily employed.

In the device of Fig. l the center recess D faces the center of the circle, whereas in the device of Fig. 4 the projecting element 35 may be positioned on the center of the circle. Transparency is desirable to enable more rapid laying out of the division lines, although in some instances opaque devices may be employed. Various types of stitt plastic materials may be employed which will be resistant to moisture and atmospheric conditions.

The universal divider of the present invention is found to be particularly useful in certain metal Working where conduits are to be joined at right angles or various other angles.

In the device of Fig. 4 the opening N may have adimension Varyingfrom 4%" to 534 and the plate in Figs. lto 5 may have dimensions of 5" in height and 5 /8 in Width 3 i In the embodiment of Fig. 6' there is a plastic plate 75 having an opening 76 which receives the turning element 77. The turning element 77 has a central handle 78 with a hole 79 to fix its position by means of a pin or stylus.

The opening 76 in the outside member will have straight sides particularly at diametrically opposite gaps 81.

This will permit the lower ridge 82 on opposite sides of the rotary member 77 to be dropped into position. The undercut portions 82 will extend f or the same width as the gaps 81.

The upper ridge 83will extend around the entire periphery as indicated both in Fig. 7 and Fig. 8 and will rest upon the inturned wedge 84 which projects inwardly from the side 76 except for the gaps 81.

This arrangement will enable the turning element 77 to be dropped into position and then turned so that the undercuts 82 will engage the ridge 84 and hold the same in position.

The lower ridge 82 does not appear in the section of Fig. 8.

It will be noted that in the embodiment of Figs. 6, 7 and 8 there are graduations 85 around the periphery of the opening 76 in the plate 75 and that there will also be diametrically opposite slots 86 which will be similarly graduated at 87.

The openings 88 will permit marking at opposite points of the position of the turning element 77.. The divisions a may range from 2-13 and there may be a number of sub-divisions ranging up to 26 or 52.

It is thus apparent that the applicant has provided a simple, readily applicable circle divider device which may be Widely utilized for certain metal layout arrangements, and which enables the sheet metal worker, without complicated tables or charts, to make numerous layouts in a very short time.

While there has been illustrated and described herein the preferred embodiments of the invention, it is to be understood that the applicant does not limit himself to the precise construction herein disclosed, and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.

Having now particularly described and ascertained the nature of the invention, and in what manner the same is to be performed, what is claimed is:

A universal circle divider for laying out sheet metal piping whereby a circle is divided into equal parts for projection lines for layout enabling cutting sheet metal comprising a clear plastic plate of trapezoidal shape with a bottom edge, a left side edge perpendicular to the bottom edge, an interrupted top edge perpendicular to the left side edge and a right oblique edge extending downwardly obliquely to the right, said plate having a circularrecess with a peripherally projecting ridge, said recess projecting through and interrupting the topedge and the portions of the top edge adjacent the recess being bevelled inwardly obliquely so as to be perpendicular to the recess and a rotatable disk extending beyond 'saidinterrupted edge snapped into said recess and rotatable therein, having a peripheral groove to fit on and receive said ridge, said rotatable disk having'diametrically oppositely positioned openings for insertion of a scriber and having diametrical ly opposite radially extending slots on each side of the center of the disk 90 away from said openings, the edges of the circular recess being graduated in degreesand the edges of the slots being graduated in. inches, said disk having a central upwardly projecting handle to rotate the disk within the circular recess.

References Cited in the file of this patent UNITED STATES PATENTS 647,339 Thompson Apr. 10, 1900 1,111,174 Ostringer Sept. 22, 1914 1,132,272 Jacobs Mar. 16, 1915 1,154,673 Van Ness Sept. 28, 19.15 1,464,417 Garland Aug. 7, 1923 1,485,674 Suiter Oct. 25, 1929 1,751,366 Shaub Mar. 18, 1930 1,945,987 Ware Feb. 6, 1934 2,049,245 Breitbarth July 28, 1936 2,190,071 Keppers Feb. 13, 1 940 2,393,873 Thurston Ian. 29, 1946 2,480,914 Gallington et al Sept. 6, 1949 FOREIGN PATENTS 68,261 Denmark Dec. 27, 1948 276,736 Switzerland Oct. 16, 1951 1,058,635 France Nov. 4, 1953 

